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@ue-too/board / KmtInputContext

Interface: KmtInputContext ​

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:609

Context interface for the Keyboard/Mouse/Trackpad (KMT) input state machine.

Remarks ​

This context provides the state and behavior needed by the KMT state machine to:

  1. Track cursor positions for calculating pan deltas
  2. Distinguish between mouse and trackpad input modalities
  3. Access canvas dimensions for coordinate transformations
  4. Manage coordinate system alignment (inverted Y-axis handling)

Input Modality Detection: The context uses a scoring system (kmtTrackpadTrackScore) to differentiate between mouse and trackpad input, which have different zoom behaviors:

  • Mouse: Ctrl+Scroll = zoom, Scroll = pan
  • Trackpad: Scroll = zoom (no Ctrl needed), Two-finger gesture = pan

Coordinate System: The alignCoordinateSystem flag determines Y-axis orientation:

  • true: Standard screen coordinates (Y increases downward)
  • false: Inverted coordinates (Y increases upward)

This interface extends BaseContext from the @ue-too/being state machine library, inheriting setup() and cleanup() lifecycle methods.

Extends ​

  • BaseContext

Properties ​

addKmtTrackpadTrackScore() ​

addKmtTrackpadTrackScore: () => void

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:625

Increases the score toward mouse

Returns ​

void

alignCoordinateSystem ​

alignCoordinateSystem: boolean

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:611

Whether to use standard screen coordinate system (vs inverted Y-axis)

cancelCurrentAction() ​

cancelCurrentAction: () => void

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:617

Cancels the current action and resets cursor position

Returns ​

void

canvas ​

canvas: Canvas

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:613

Canvas accessor for dimensions and cursor control

initialCursorPosition ​

initialCursorPosition: Point

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:619

The cursor position when a pan gesture started

kmtTrackpadTrackScore ​

kmtTrackpadTrackScore: number

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:621

Score tracking input modality: >0 for mouse, <0 for trackpad, 0 for undetermined

mode ​

mode: "kmt" | "trackpad" | "TBD"

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:629

The current input modality: 'kmt' (mouse), 'trackpad', or 'TBD' (to be determined)

setInitialCursorPosition() ​

setInitialCursorPosition: (position) => void

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:615

Sets the initial cursor position when starting a pan gesture

Parameters ​

position ​

Point

Returns ​

void

setMode() ​

setMode: (mode) => void

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:627

Sets the determined input modality

Parameters ​

mode ​

"kmt" | "trackpad" | "TBD"

Returns ​

void

subtractKmtTrackpadTrackScore() ​

subtractKmtTrackpadTrackScore: () => void

Defined in: packages/board/src/input-interpretation/input-state-machine/kmt-input-context.ts:623

Decreases the score toward trackpad

Returns ​

void

Methods ​

cleanup() ​

cleanup(): void

Defined in: packages/being/dist/interface.d.ts:31

Returns ​

void

Inherited from ​

BaseContext.cleanup

setup() ​

setup(): void

Defined in: packages/being/dist/interface.d.ts:30

Returns ​

void

Inherited from ​

BaseContext.setup